1. Field of the Invention
The invention is related generally to an image beam adjustment method, and more particularly to an image beam adjustment method of a pair of viewing glasses.
2. Description of Related Art
As science and technology rapidly progress, in addition to striving for thinness and compactness of the display device, a major goal with regards to the area of display technology development is in the display of stereoscopic images. Generally speaking, the principle behind a stereoscopic image is sending two different images to the left and right eyes, and having the brain construct a three-dimensional (3D) image.
Currently, 3D display technologies may be generally categorized into two types, a stereoscopic type of display technologies which require a user to wear viewing glasses and an auto-stereoscopic type which does not require the viewing glasses. The viewing glasses type may be further divided into the early red and blue glasses, the shutter glasses, and the polarizing glasses nowadays. Irrespective of the type of viewing glasses, the main principle behind rendering a 3D image is having the left and right eye view different images, so that the brain views the images as a 3D image. Current 3D shutter glasses typically complement display devices such as a 3D liquid crystal television and a 3D projector to render a 3D effect.
A conventional pair of shutter glasses includes a front polarizer, a liquid crystal layer, and a back polarizer. A polarization axis direction of the front polarizer is parallel to a polarization direction of an image beam emitted from the 3D display device, and the polarization axes of the front and back polarizers are orthogonal. The liquid crystal layer is interposed between the front and back polarizers. Moreover, the liquid crystal layer is controlled by an operating voltage to alter the polarization direction of the image beam, such that after the image beam passes through the liquid crystal layer, the polarization direction of the image beam can be oriented as parallel or perpendicular to the back polarizer, so that the polarizer can block the image beam or allow the image beam to pass. By applying voltages to the left and right lenses of the shutter glasses in sequence, the shutter glasses can block the left and right images transmitted from the 3D display device at different times. Accordingly, a left eye of a viewer sees a left eye image, a right eye of the viewer sees a right eye image, and the brain of the viewer stacks the images to form a 3D image.
Although the conventional shutter glasses may achieve the effect of 3D imaging by complementing the 3D display device, there is no unified standard for the polarization direction of the image beam transmitted by the currently available 3D display devices on the market. In other words, different display devices may have image beams of different polarization directions. Therefore, a pair of shutter glasses having a particular polarization direction can only be used to complement a display device having the corresponding polarization direction. Consequently, not only is a manufacturer faced with increases in the production cost and the price for a pair of viewing glasses, the user is faced with unnecessary wastes due to the need to purchase different types of viewing glasses.